#ifndef _TRON_H
#define _TRON_H

class function
{
public:
  virtual double fun(double *w) = 0;

  virtual void grad(double *w, double *g) = 0;

  virtual void Hv(double *s, double *Hs) = 0;

  virtual int get_nr_variable(void) = 0;

  virtual ~function(void)
  {
  }
};

class TRON
{
public:
  TRON(const function *fun_obj, double eps = 0.1, int max_iter = 1000);
  ~TRON();

  void tron(double *w);

  void set_print_string(void (*i_print) (const char *buf) );

private:
  int trcg(double delta, double *g, double *s, double *r);

  double norm_inf(int n, double *x);

  double    eps;
  int       max_iter;
  function *fun_obj;
  void info(const char *fmt, ...);

  void (*tron_print_string)(const char *buf);
};
#endif
